Efficiency based optimal control of Kaplan hydrogenerators

Journal Article · Thu Jun 01 04:00:00 EDT 1995 · IEEE Transactions on Energy Conversion

DOI:https://doi.org/10.1109/60.391902· OSTI ID:94103

Schniter, P; Wozniak, L ^[1]

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1. Univ. of Illinois, Urbana, IL (United States)

This paper investigates an optimal strategy for controlling the speed response of Kaplan hydrogenerating systems to decreases in load. Typically, primary control gates restrict to redirect water through the turbine to stabilize and transfer the system to operating point demand. The adjustable turbine blade angle is used to return to maximum operating efficiency at the new load level. The over-speed reduction is limited by the conduit`s ability to withstand the over-pressure caused by the flow restriction at the turbine. A control scheme using gates and blades simultaneously and independently is developed. The initial action of the proposed control moves the gates and blades in opposite directions at maximum rates in an effort to reduce efficiency without altering flow, thus quickly decreasing the generated power while affecting the pressure minimally. The final control action moves the gears and blades simultaneously to restore maximum efficiency operation at the new power level demand. Similarities are found when comparing the efficiency based control to the Bang-bang and Linear Quadratic Regulator results of optimal control theory, though attempting to apply either of these methods directly to this problem is impractical. Simulation results show that the proposed scheme outperforms the traditional gate-dominant control in minimizing turbine over-speed and speed settling time under prescribed load change and conduit pressure limits. However, in its present form, the design is found to be more sensitive to system nonlinearities than its conventional counterpart.

• OSTI ID: 94103
• Report Number(s): CONF-940702--
• Journal Information: IEEE Transactions on Energy Conversion, Journal Name: IEEE Transactions on Energy Conversion Journal Issue: 2 Vol. 10; ISSN 0885-8969; ISSN ITCNE4
• Country of Publication: United States
• Language: English

Related Subjects

13 HYDRO ENERGY
CONTROL
CONTROL SYSTEMS
HYDRAULIC TURBINES
HYDROELECTRIC POWER PLANTS
OPTIMIZATION
POWER DEMAND
SPEED REGULATORS